This invention relates to a method of carrying out a buffer output processing for a file device concurrently renewed by a plurality of renewal processing programs by using a system shared buffer unit which the renewal processing program can use in common. This invention relates also to a buffer asynchronous output apparatus for use in carrying out the method.
As well known in the art, a system shared buffer unit is interposed between a plurality of renewal processing programs and a file device. The renewal processing programs can use the system shared buffer unit in common. The file device is concurrently renewed by the renewal processing programs. The system shared buffer unit comprises a plurality of buffer areas. Attention will be directed to a case as follows. For example, after a first renewal processing program renews one of the buffer areas as a renewed buffer area, a second renewal processing program wants to refer to or renew the renewed buffer area. Under the circumstances, in prior art, the second renewal processing program can refer to or renew the renewed buffer area only after the contents of the renewed buffer area are completely outputted into the file device. In other words, it is necessary that the second renewal processing program awaits completion of file output for the renewed buffer area. As a result, such a buffer output processing system for a file device has reduced efficiency.